Matthew 23:8-12

But be not ye called Rabbi: for one is your teacher, and all ye are brethren. And call no man your father on the earth: for one is your Father, even he who is in heaven. Neither be ye called masters: for one is your master, even the Christ. But he that is greatest among you shall be your servant. And whosoever shall exalt himself shall be humbled; and whosoever shall humble himself shall be exalted.